Technical Field
The present disclosure relates to a method and a device for controlling an apparatus such as a computer, a smartphone, a digital tablet, a GPS navigation device, a large display screen, a set-top box, etc.
Description of the Related Art
For this purpose, one well-known method involves using a pointing device such as a mouse or a tactile surface which can be arranged on the display screen of the apparatus. However, using a mouse is not suited to small apparatuses such as smartphones, digital tablets and navigation devices. Using a mouse is not suited either to the introduction of commands in connection with an image displayed remotely on a television set. Tactile surfaces arranged on a display screen can be soiled and thus affect the visibility of the screen. Some apparatuses such as smartphones can be equipped with a pico projector projecting an image. A tactile surface is thus not suited to generating commands from finger movements in connection with the image projected. Furthermore, tactile surfaces must have a certain minimum surface area. They are not suited either to the introduction of commands on a conventional size remote control in connection with an image remotely displayed on a large screen.
Furthermore, distance measurement devices exist which assess a distance with an object based on a propagation time of a photon beam emitted in the form of pulses and reflected on the object. For this purpose, these devices light up a detection field with a pulsed light source such as a pulsed laser source, and detect photons reflected by an object present in the detection field. To detect the reflected photons, these devices can comprise one or more reverse biased photodiodes so that an avalanche phenomenon occurs upon receiving a flow of photons. Each of the measurement devices may also comprise one or more single photon avalanche diodes (SPAD) each being capable of generating a detection signal upon receiving a photon having particular characteristics (e.g., a unique photon). The distance of the object present in the detection zone is assessed on the basis of the propagation time or time of flight (TOF) between the instant of emission of a light pulse and the instant a pulse appears in the signal supplied by the detection device. The measurement accuracy depends particularly on the duration of the light pulses emitted by the source, and the shorter these pulses are, the more accurate the measurement can be. However, the accuracy that can be obtained with such a distance measuring device proves insufficient to detect finger movements such as those made on a tactile surface.